BACKGROUND AND PURPOSE:

• Renal dysfunction is associated with preeclampsia, especially in the setting of severe preeclampsia
• Kristensen et al. (BMJ, 2019) sought to determine if preeclampsia may be also be associated with later onset kidney disease

METHODS:

• Nationwide register-based cohort study
• Participants
  • ≥1 pregnancy lasting at least 20 weeks
• Exposure: Preeclampsia
  • Validated against ACOG 2002 definitions
  • Diagnoses must be registered at least once in a window of 1 month prior to delivery or 7 days postpartum
  • Diagnoses only registered prior to 20 weeks not included
• Primary outcome: Rates of kidney disease between women with and without a history of pre-eclampsia
  • Must have occurred at least 3 months postpartum
  • Diagnosis of moderate or severe: Hypertensive kidney disease | Glomerular disease | Chronic tubulointerstitial nephritis | Renal failure
• Data Analysis
  • Hazard ratios (HR), estimated using Cox regression
  • Stratified by gestational age because preterm birth also associated with future kidney disease

RESULTS:

• 1,072,330 women | 19,994,470 person years
  • Average follow up 18.6 years/woman
  • 14,816 cases of kidney disease
• Women with a history or preeclampsia were more likely to develop any chronic renal conditions compared to those without a history of preeclampsia
  • Early preterm (<34 weeks) preeclampsia: HR 3.93 (95% CI, 2.90 to 5.33)
  • Late preterm preeclampsia (34-36 weeks): HR 2.81 (95% CI, 2.13 to 3.71)
  • Term preeclampsia (≥37 weeks): HR 2.27 (95% CI, 2.02 to 2.55)
• Strong associations were found for
  • Chronic kidney disease
    • HR 2.90 for early preterm | HR 2.24 for late preterm | 2.27 for term
  • Hypertensive kidney disease
    • HR 4.19 for early preterm | HR 3.69 for late preterm | HR 3.06 for term
  • Glomerular/proteinuric disease
    • HR 5.34 for early preterm | HR 3.40 for late preterm | HR 2.14 for term
• Adjustment for CVD and hypertension did reduce the association but only partially
• Associations between preeclampsia and chronic kidney disease and glomerular/proteinuric disease were stronger within 5 years of latest pregnancy
  • ≤5 years since pregnancy
    • Chronic kidney disease: HR 6.11 (95% CI, 3.84 to 9.72)
    • Glomerular/proteinuric disease: HR 4.77 (95% CI, 3.88 to 5.86)
  • >5 years since pregnancy
    • Chronic kidney disease: HR 2.06 (95% CI, 1.69 to 2.50)
    • Glomerular/proteinuric disease: HR 1.50 (95% CI, 1.19 to 1.88)
• Associations were strong for chronic renal disease, as opposed to acute

CONCLUSION:

• Preeclampsia was strongly associated with later onset chronic renal disease, particularly at earlier gestational ages and within 5 years from delivery
• The authors conclude that earlier detection of renal disease could help preserve more function
• Future research would address appropriate follow-up and interventions to maximize renal function

Learn More – Primary Sources:

Pre-eclampsia and risk of later kidney disease: nationwide cohort study

Related ObG Topics:

Diagnosing Preeclampsia – Key Definitions and ACOG Guidelines

ACOG Preeclampsia Guidelines: Antenatal Management and Timing of Delivery

ACOG Guidance: Emergency Treatment for Severe Hypertension in Pregnancy

Does Placental Growth Factor Lead to a Quicker Diagnosis in Women with Suspected Pre-Eclampsia?

Is Eclampsia in Pregnancy Linked with Greater Risk for Seizure Disorder?